Fix: add consumer wake up pipe to avoid race

[lttng-tools.git] / src / common / consumer.h

diff --git a/src/common/consumer.h b/src/common/consumer.h
index 6eb5b61bb25b806d12c8cea2262a70329c87fcff..4ac823c017d03754ed545a9a1288df707b84778f 100644 (file)
--- a/src/common/consumer.h
+++ b/src/common/consumer.h
@@ -32,7 +32,7 @@
 #include <common/compat/uuid.h>
 #include <common/sessiond-comm/sessiond-comm.h>
 #include <common/pipe.h>
-#include <common/index/lttng-index.h>
+#include <common/index/ctf-index.h>
 
 /* Commands for consumer */
 enum lttng_consumer_command {
@@ -41,7 +41,7 @@ enum lttng_consumer_command {
        /* pause, delete, active depending on fd state */
        LTTNG_CONSUMER_UPDATE_STREAM,
        /* inform the consumer to quit when all fd has hang up */
-       LTTNG_CONSUMER_STOP,
+       LTTNG_CONSUMER_STOP,    /* deprecated */
        LTTNG_CONSUMER_ADD_RELAYD_SOCKET,
        /* Inform the consumer to kill a specific relayd connection */
        LTTNG_CONSUMER_DESTROY_RELAYD,
@@ -57,6 +57,7 @@ enum lttng_consumer_command {
        LTTNG_CONSUMER_FLUSH_CHANNEL,
        LTTNG_CONSUMER_SNAPSHOT_CHANNEL,
        LTTNG_CONSUMER_SNAPSHOT_METADATA,
+       LTTNG_CONSUMER_STREAMS_SENT,
 };
 
 /* State of each fd in consumer */
@@ -156,11 +157,16 @@ struct lttng_consumer_channel {
 
        /* Metadata cache is metadata channel */
        struct consumer_metadata_cache *metadata_cache;
-       /* For metadata periodical flush */
+       /* For UST metadata periodical flush */
        int switch_timer_enabled;
        timer_t switch_timer;
        int switch_timer_error;
 
+       /* For the live mode */
+       int live_timer_enabled;
+       timer_t live_timer;
+       int live_timer_error;
+
        /* On-disk circular buffer */
        uint64_t tracefile_size;
        uint64_t tracefile_count;
@@ -329,6 +335,15 @@ struct lttng_consumer_stream {
         * FD of the index file for this stream.
         */
        int index_fd;
+
+       /*
+        * Rendez-vous point between data and metadata stream in live mode.
+        */
+       pthread_cond_t metadata_rdv;
+       pthread_mutex_t metadata_rdv_lock;
+
+       /* Indicate if the stream still has some data to be read. */
+       unsigned int has_data:1;
 };
 
 /*
@@ -441,6 +456,19 @@ struct lttng_consumer_local_data {
        int consumer_splice_metadata_pipe[2];
        /* Data stream poll thread pipe. To transfer data stream to the thread */
        struct lttng_pipe *consumer_data_pipe;
+
+       /*
+        * Data thread use that pipe to catch wakeup from read subbuffer that
+        * detects that there is still data to be read for the stream encountered.
+        * Before doing so, the stream is flagged to indicate that there is still
+        * data to be read.
+        *
+        * Both pipes (read/write) are owned and used inside the data thread.
+        */
+       struct lttng_pipe *consumer_wakeup_pipe;
+       /* Indicate if the wakeup thread has been notified. */
+       unsigned int has_wakeup:1;
+
        /* to let the signal handler wake up the fd receiver thread */
        int consumer_should_quit[2];
        /* Metadata poll thread pipe. Transfer metadata stream to it */
@@ -500,7 +528,7 @@ struct lttng_consumer_global_data {
 /*
  * Init consumer data structures.
  */
-void lttng_consumer_init(void);
+int lttng_consumer_init(void);
 
 /*
  * Set the error socket for communication with a session daemon.
@@ -582,6 +610,7 @@ struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
                uint64_t net_seq_idx);
 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key);
 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream, char *path);
+int consumer_send_relayd_streams_sent(uint64_t net_seq_idx);
 void close_relayd_stream(struct lttng_consumer_stream *stream);
 struct lttng_consumer_channel *consumer_find_channel(uint64_t key);
 int consumer_handle_stream_before_relayd(struct lttng_consumer_stream *stream,
@@ -600,15 +629,17 @@ ssize_t lttng_consumer_on_read_subbuffer_mmap(
                struct lttng_consumer_local_data *ctx,
                struct lttng_consumer_stream *stream, unsigned long len,
                unsigned long padding,
-               struct lttng_packet_index *index);
+               struct ctf_packet_index *index);
 ssize_t lttng_consumer_on_read_subbuffer_splice(
                struct lttng_consumer_local_data *ctx,
                struct lttng_consumer_stream *stream, unsigned long len,
                unsigned long padding,
-               struct lttng_packet_index *index);
+               struct ctf_packet_index *index);
 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream);
 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
                unsigned long *pos);
+int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream);
+int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream);
 void *consumer_thread_metadata_poll(void *data);
 void *consumer_thread_data_poll(void *data);
 void *consumer_thread_sessiond_poll(void *data);
@@ -622,7 +653,7 @@ int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream);
 int consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
                struct lttng_consumer_local_data *ctx, int sock,
                struct pollfd *consumer_sockpoll, struct lttcomm_relayd_sock *relayd_sock,
-               uint64_t sessiond_id);
+               uint64_t sessiond_id, uint64_t relayd_session_id);
 void consumer_flag_relayd_for_destroy(
                struct consumer_relayd_sock_pair *relayd);
 int consumer_data_pending(uint64_t id);